In multi-storey buildings, the formation of the floor of each successive storey involves pouring concrete into formwork with each floor generally extending out to the periphery of the building from a central core structure. Curtain walls are walls that extend between each concrete floor but do not bear any weight, as the curtain walls are suspended between the floors. These can include interior walls or exterior walls, with the exterior walls commonly being made from glass.
A common occurrence in a building above a certain height is when the building is subjected to high wind resulting in creaking, groaning or grating noises emanating from the connection of a curtain wall or stud wall to the underside of the slab floor. The underside of such a floor serves as the ceiling or roofing structure of the particular space where the stud wall or curtain walls exists. These noises are annoying and worrying to occupants of the building, particularly when the occupants are trying to rest, to the extent that some occupants are forced to vacate the building.
Previously the grating, groaning or creaking noises had been identified as originating from top head tracks, particularly deflection head tracks, associated with a curtain or stud wall. Part of the stud that connects to or is secured to the deflection head track rubs against the interior of the head track to create the noise. In order to overcome this, users had inserted strips of plastic to prevent the rubbing or grating of the stud against the head track. However a more fundamental cause of the noise has been identified as originating from the interface between the underside of the slab floor that forms the ceiling of a room, and the attachment of a head track to that underside. Generally, when concrete is poured into the formwork to form a concrete slab floor, it cures over time and, although the top surface of the slab is made smooth by building workers, the underside of the slab presents an uneven surface. When the head track is secured to the underside surface through a series of fasteners, the unevenness of the underside surface creates tension at various points along the C-channel shaped head track. This results in the legs or flanges of the track being splayed inwardly or outwardly depending on the gap between the surface of the slab and the web of the track. Thus the legs may be splayed inwardly when there is a relatively large gap between the track and surface, with fasteners securing the web to the surface at predefined distances. Furthermore where the surface of the slab pushes or compresses against the web of the track, then the legs can be splayed outwardly. When the studs are connected to the track, depending on whether the particular connection point is under tension or not under tension, it will produce noise under certain wind speeds that the building is subjected to. Thus, for example, a track that is under tension and the legs of the track splayed inwardly or outwardly, reacts to the wind load on the curtain wall, thus producing noise.
The present invention provides a track that, in a preferred form, is able to maintain a substantially straight profile so that connection of a stud at any location along the track will not produce any creaking or grinding noise due to contact between the stud and the track, in a high wind event.